"In the last eight years you've come to Youtube to watch, share and fall in love with videos from all over the world. Tens of thousands of partners have created channels that have found and built businesses for passionate, engaged audiences," it said in a blog post.

"Advertisers have taken notice: all of the Ad Age Top 100 brands are now running campaigns on Youtube. And today, we're announcing a new milestone: Youtube now has more than a billion unique users every single month."

That's a big number, and Youtube has helpfully worked out what it means for us in real terms.

It says that nearly one out of every two people on the internet visits Youtube, and that if Youtube were a country, it would be the third largest in the world after China and India. Imagine that, all those people watching Gangnam Style and cute cat videos in one place.

"From the aspiring filmmaker in his basement and the next great pop musician, to the fans all around the world who tune in, subscribe and share their favorite videos with the planet, thank you for making Youtube what it is today," added Youtube in its blog post. "You have truly created something special."

A study of what has attracted so many eyeballs to Youtube found a group of people called Generation C. These people, defined by ratings service Nielsen, are always connected and always connecting.

In a Google Adwords agency blog Generation C is described as people who grew up with Youtube and now engage with it on many devices as often as possible. We think we've seen them. We think of them as annoying kids. "Gen C" is the abbreviation the Google Adwords agency blog uses.

"Gen C watches Youtube on all screens, constantly switching between devices," said the blog.

"Gen C is deeply engaged with online video, watching, creating and uploading videos on YouTube. Gen C thrive on community, defining what's popular on YouTube by sharing videos with friends and family. Gen C is made up of expert curators who care about finding content that matters to them."

These people hover around the world, apparently waiting for the next chance to watch a panda get alarmed when another sneezes or a monkey sniff something that really it ought to know better than to sniff.

"Gen C watches Youtube on their smartphones as a complementary activity to their lives," added the beguiling blog.

"For example, 41 percent tune in to Youtube on their smartphone while waiting for something [or] someone, 18 percent while commuting from work or school, and 15 percent tune in while commercials are running on TV."

We don't know what percentage have heard of the word "hobby". We suspect it is quite low.

By the way, Gangnam Style, which we have embedded below, has now been seen one billion, four hundred fifty-one million, four hundred seventy-one thousand and one hundred times. µ